by
Blitzer, Robert F.

Answer

$\frac{7}{10}$ = 0.7 but $\frac{7+5}{10 + 5}$ = $\frac{12}{15}$ = 0.8

Work Step by Step

Let us consider a fraction initially.
$\frac{7}{10}$ The value of this fraction is 0.7
Now, adding the same number '5' to the numerator and denominator, the value of the fraction becomes 0.8.
$\frac{7+5}{10 + 5}$ = $\frac{12}{15}$ = 0.8